I have just split from my girlfriend of 3 years.we have got a baby girl of only 4 weeks.I had to leave because when we fight she gets in my face.she has hit me a couple of times.I have had to hold her on the floor just to stop her.this has happened about 5 times.I didn't wan o leave my baby girl but I feel like I need to due to a new born being round it all.all I want is what is best from my baby girl.we have tried sorting this out but we always end up how we were.I am wrongin leaving I baby girl?please tell me.

I suggest you seek legal help with the intention of seeking visitation.

You need to establish a level of custody, if that be joint, or merely visitation, so you need to file with the court.